CS 775: Advanced Computer Graphics. Lecture 17 : Motion Capture

Transcription

1 CS 775: Advanced Computer Graphics Lecture 17 :

2 History Study of human motion Leonardo da Vinci ( )

3 History Study of human motion Edward J. Muybridge,

4 Capturing motion of a performer in 3D The idea for using Mocap in animation comes from rotoscoping

5 Capturing motion of a performer in 3D Has many uses: Animation Sports Ergonomics Medicine Robotics

6 Types of Motion capture Mechanical Gyro at the hips Magnetic Potentiometers at joints change voltage according to angular rotation of the rods. motion capture system mocap.htm Magnetic sensors and transmitters.

7 Types of Motion capture Inertial Single Accelerometers MEMS Gyroscopes Other sensors

8 Types of Motion capture Optical

9 Types of Motion capture Optical With Markers Phasespace Active

10 Phasespace Types of Motion capture Optical With Markers Active Passive Vicon

11 Optical Motion capture Cameras Vicon MX: Cameras with (near) infrared LED's: 4M pixels, 10 bit grayscale, 166 fps Phasespace: Linear detectors, 12.4M pixels, 480fps

12 Types of Motion capture Optical With Markers Active Passive Markerless Monocular Human with a Mixture of Regressors, A Agarwal and B. Triggs, CVPR 2005 Monocular Kinect v1, v2 Real Time Human Pose Recognition in Parts from Single Depth Images, Shotton et al., CVPR 2011

13 Types of Motion capture Optical With Markers Active Passive Markerless Monocular Multi camera 3D Human Kinematic Modeling and Markerless Motion Capture, G. Cheung, S. Baker, T. Kanade, CVPR2003 Articulated Mesh Animation from Multi view Silhouettes, Dl Vlasic, I. Baran, W. Matusik, J. Popović, ACM TOG, 2008

14 Facial Motion capture Scale of movement is different from full body capture Skin is not rigid Performance Capture Full body and face

15 Processing Pipeline Calibrate, reconstruct markers and label Markers reconstructed in 3D Labelling in a T frame Full Labelling

16 Processing Pipeline Complete motion trajectories Processing marker CS775: Lecture 17 trajectories

17 Processing Pipeline Export the animation BVH ASF/AMC C3D

18 BVH BioVision Hierarchy Format HIERARCHY ROOT Hips { OFFSET CHANNELS 6 Xposition Yposition Zposition Zrotation Xrotation Yrotation JOINT Chest { OFFSET 5.21 CHANNELS 3 Zrotation Xrotation Yrotation JOINT Neck { OFFSET CHANNELS 3 Zrotation Xrotation Yrotation JOINT Head { OFFSET 5.45 CHANNELS 3 Zrotation Xrotation Yrotation End Site { OFFSET 3.87 } } }

19 BVH BioVision Hierarchy Format MOTION Frames: 2 Frame Time: